Thomas o



'(No Mqdel.) I. 0.- HUTGHINSON.

HYDRAULIC JACK. v N0. 280,315. Patented June 26, 1883;

Whine/gnaw. V I .Zivvewfan 4 UNITED STATES FFICE.

THOMAS O. HUTCHINSON, OF SALE ASSIGNOR ,OF ONE-HALF TO ADDISON O. GIBBS, OF PORTLAND, OREGON.

HYDRAULIC JACK.

SPECIFICATION forming part of Letters Patent No. 280,315, dated June 26, 1883.

- Application filed February a, 1883. (No model.)

T all whonzl it may concern:

Be it known that I, THOMAS O. HUTOHIN- SON, a citizen of the United States, residing at Salem, Marion county, in the State of Oregon,

have invented certain new and useful Improvements in Hydraulic Jacks, by which they may be used in any position and by which the mode of accelerating speed is simplified and made more practical,ofwhich the followingisaspeci- 1o fication, reference being had to the accompanying diagrams.

My invention consists, first, in a plug or follower so fitted into the reservoir as to make an air-tight stopper, and which, as the liquid 1 is pumped out of the reservoir, is forced by the pressure of the atmosphere from without to follow the receding liquid, holding it in place so that it cannot fall away from the, pumps, whatever he the position oft-he jack; second,

in a combination Of' pistons in which a larger piston forms the cylinder for a smaller piston,

whereby all the pistons may be operated together to produce the effect of one large piston, Or the smaller piston may be operated alone to raise the jack more slowly, and consequently with greater power. One set of ingress and egress valves is suilicient for all of the pumps. Y

Figure 1 is a vertical section of the jack 3o partly raised, showing thelargest piston at the greatest height and the smallest one at its lowest point. Fig. 2 is a cross-section of the jack at the line 5 6. Fig. 3 is a perspective view of the 'follower.

A is the hoistirig-cylinder of the jack;

- B" is the ram, and B is the reservoirtherein, which is bored out true for'the passage of the follower l). 1 p

O is a plug, which is secured in the top of 0 the ram to compress the packing-in the space X, and to serve as the head of the ram. The plug'U may also serve, as in the present instance, as the barrel for the larger piston F. The larger piston 1 serves as the barrel for the smaller piston H,whichin turn may serve asthe'barrel fora smaller piston. (Not here represented) The smaller piston H is provided with a port, 2', and any common checkvalve, J. The piston'F is provided with two ports,'n k. lis the check-valve on the lttllb.

plug G,which valve is provided with the stem or, protruding into the space E in the plugC. e is the piston-rod of the :piston' F,'and is hollow to admit of the passage of the piston,

rod 9 of the piston H thronglrit, and in case of a third pump and piston-rod, the rod g must also be hollow for the passage of-said third rod, and so on. The inside rod is solid. The crosshead is screwed on thehollow rod 6, forming a stuffing-box, a, to prevent the escape of the liquid through said' hollow-rodi This cross-1 head is furnished with the ordinary slot, 1, for the reception of the'ordinary rock-lever V,

Fig. 2. The cross-head for the inside rod needs no stuffing-box, the rod being solid. The rockshafts X Y are hollow, exceptth'e inside one, which is solid, one working through the other, as shown in Fig. 2. The rock-shafts have each a wheel or circular head, a, on the outer end,

of equal size. The handle, or lever b has a circular opening in one end,which fits over the heads a a, and is of such width as to cover both, and is provided withthumb-screws ed, p

by which the lever-b is fastened to either or both of the heads a (1, whereby either or both of the rock-shafts X Y may be rocked, and consequently any of the pistons operated".

Operation: XVhen both pistons are usedthey are first moved to the end of their downstroke, when the water runsthrough the port a into I the space E. On the next upstroke the piston H is first moved to cover the port n,to prevent the return of the -water,when bothpiston's are' operated to complete the strok e together, thereby forcing the water in the space E. through the checlcvalve into the space A',Whieh elevates the hoisting-cylinder A.

The operation of the'piston H wlrienused alone is as follows:

On the upstroke, as soon as it passes the port 11, the water in the spaceE G-is prevented from returning, and forced into the hoisting-cylin.- der through the check-valve I. On the downstroke a vacuum is formed aboye the piston H,

which is filled by the water passing through the ports k i when the operation is repeated. Ordinarily the piston F is not given-a full upstroke, and the check-valve I therefore pre-- vents. the esea pe bf ttnyfwater jfffmi the statee. A; but when the hoistihgpylinder'A:is;e1e-' 1 vategi and it is desired to l ewer it; the pisto'fl 'F is givenefull upstr0ke,1,andstrikes the pin 5 M,which elevatesthe Valve lend permits the.

10 1;.111 'hydrau1ie'jacks, the eemhii atien 0ft".

' faiirheadfiwo 'pist0ns,-F H, one of the pistons serving'as the barrel of the other 'and bot/1101).,

" ti'al ly as described;

rating with bne. set of waives, Z J, ,substen- 2 .fIn hjfli-eiiliejeksg the 'eembinati eii ofef .rairn, IB, having the 'reser'vqir B','a followi; D,

and a pump, substantially as..described.' 3. In hydraulic jacks, themeehanisni for 0 .ei'atilfg two pistons together or independently, consisting of the roek shafts X.' Y; one, within the other, the lever, b, t11e heads a, a ndjthe thumb s erews c d, substa1 1 ti al:Iy as :desfi'ihed.

l Witnesses: 

